A smart phone may have a wireless large area network (LAN) having a power amplifier integrated with the transceiver. In order for the power amplifier to provide a high linear output power, amplifier pre-distortion may be used to compensate for distortions in the power amplifier. In a system using I-Q modulation and de-modulation, a signal has in-phase (I) and quadrature-phase (Q) components that are processed through I and Q channels, respectively. Each path may include components such as a mixer, a low pass filter, and an analog-to-digital converter. The mismatches between the components in the I and Q paths reduce the quality of the signal. In order to achieve a high performance in the amplifier pre-distortion, it is preferable to remove imbalance between in-phase and quadrature channel signals.